package cn.dm.common;

import javax.imageio.ImageIO;
import javax.imageio.ImageReader;
import javax.imageio.stream.ImageInputStream;
import java.awt.image.BufferedImage;
import java.io.*;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Map.Entry;

public class FileType {

    public final static Map<String, String> FILE_TYPE_MAP = new HashMap<String, String>();

    private FileType(){}
    static{
        getAllFileType();  //初始化文件类型信息    
    }
    /**
     * Created on 2010-7-1   
     * <p>Discription:[getAllFileType,常见文件头信息]</p>  
     * @author:[shixing_11@sina.com]
     */
    private static void getAllFileType()
    {
        FILE_TYPE_MAP.put("jpg", "FFD8FF"); //JPEG (jpg)    
        FILE_TYPE_MAP.put("png", "89504E47");  //PNG (png)    
        FILE_TYPE_MAP.put("gif", "47494638");  //GIF (gif)    
        FILE_TYPE_MAP.put("tif", "49492A00");  //TIFF (tif)    
        FILE_TYPE_MAP.put("bmp", "424D"); //Windows Bitmap (bmp)    
        FILE_TYPE_MAP.put("dwg", "41433130"); //CAD (dwg)    
        FILE_TYPE_MAP.put("html", "68746D6C3E");  //HTML (html)    
        FILE_TYPE_MAP.put("rtf", "7B5C727466");  //Rich Text Format (rtf)    
        FILE_TYPE_MAP.put("xml", "3C3F786D6C");
        FILE_TYPE_MAP.put("zip", "504B0304");
        FILE_TYPE_MAP.put("rar", "52617221");
        FILE_TYPE_MAP.put("psd", "38425053");  //Photoshop (psd)    
        FILE_TYPE_MAP.put("eml", "44656C69766572792D646174653A");  //Email [thorough only] (eml)    
        FILE_TYPE_MAP.put("dbx", "CFAD12FEC5FD746F");  //Outlook Express (dbx)    
        FILE_TYPE_MAP.put("pst", "2142444E");  //Outlook (pst)    
        FILE_TYPE_MAP.put("xls", "D0CF11E0");  //MS Word    
        FILE_TYPE_MAP.put("doc", "D0CF11E0");  //MS Excel 注意：word 和 excel的文件头一样    
        FILE_TYPE_MAP.put("mdb", "5374616E64617264204A");  //MS Access (mdb)    
        FILE_TYPE_MAP.put("wpd", "FF575043"); //WordPerfect (wpd)     
        FILE_TYPE_MAP.put("eps", "252150532D41646F6265");
        FILE_TYPE_MAP.put("ps", "252150532D41646F6265");
        FILE_TYPE_MAP.put("pdf", "255044462D312E");  //Adobe Acrobat (pdf)    
        FILE_TYPE_MAP.put("qdf", "AC9EBD8F");  //Quicken (qdf)    
        FILE_TYPE_MAP.put("pwl", "E3828596");  //Windows Password (pwl)    
        FILE_TYPE_MAP.put("wav", "57415645");  //Wave (wav)    
        FILE_TYPE_MAP.put("avi", "41564920");
        FILE_TYPE_MAP.put("ram", "2E7261FD");  //Real Audio (ram)    
        FILE_TYPE_MAP.put("rm", "2E524D46");  //Real Media (rm)    
        FILE_TYPE_MAP.put("mpg", "000001BA");  //    
        FILE_TYPE_MAP.put("mov", "6D6F6F76");  //Quicktime (mov)    
        FILE_TYPE_MAP.put("asf", "3026B2758E66CF11"); //Windows Media (asf)    
        FILE_TYPE_MAP.put("mid", "4D546864");  //MIDI (mid)    
    }

    public static void main(String[] args) throws Exception{
        File f = new File("d://apache-activemq-5.1.0-bin.png");
        if (f.exists()){
            String filetype1 = getImageFileType(f);
            System.out.println(filetype1);
            String filetype2 = getFileByFile(f);
            System.out.println(filetype2);
        }
    }

    /**
     * Created on 2010-7-1   
     * <p>Discription:[getImageFileType,获取图片文件实际类型,若不是图片则返回null]</p>  
     * @param File
     * @return fileType
     * @author:[shixing_11@sina.com]
     */
    public final static String getImageFileType(File f){
        if (isImage(f))
        {
            try
            {
                ImageInputStream iis = ImageIO.createImageInputStream(f);
                Iterator<ImageReader> iter = ImageIO.getImageReaders(iis);
                if (!iter.hasNext())
                {
                    return null;
                }
                ImageReader reader = iter.next();
                iis.close();
                return reader.getFormatName();
            }
            catch (IOException e)
            {
                return null;
            }
            catch (Exception e)
            {
                return null;
            }
        }
        return null;
    }

    /**
     * Created on 2010-7-1   
     * <p>Discription:[getFileByFile,获取文件类型,包括图片,若格式不是已配置的,则返回null]</p>  
     * @param file
     * @return fileType
     * @author:[shixing_11@sina.com]
     */
    public final static String getFileByFile(File file)
    {
        String filetype = null;
        byte[] b = new byte[50];
        try
        {
            InputStream is = new FileInputStream(file);
            is.read(b);
            filetype = getFileTypeByStream(b);
            is.close();
        }
        catch (FileNotFoundException e)
        {
            e.printStackTrace();
        }
        catch (IOException e)
        {
            e.printStackTrace();
        }
        return filetype;
    }

    public final static String getFileByInputStream(InputStream is){
        String filetype = null;
        byte[] b = new byte[50];
        try{
            is.read(b);
            filetype = getFileTypeByStream(b);
            is.close();
        }
        catch (FileNotFoundException e){
            e.printStackTrace();
        }catch (IOException e){
            e.printStackTrace();
        }
        return filetype;
    }

    /**
     * Created on 2010-7-1   
     * <p>Discription:[getFileTypeByStream]</p>  
     * @param b
     * @return fileType
     * @author:[shixing_11@sina.com]
     */
    public final static String getFileTypeByStream(byte[] b)
    {
        String filetypeHex = String.valueOf(getFileHexString(b));
        Iterator<Entry<String, String>> entryiterator = FILE_TYPE_MAP.entrySet().iterator();
        while (entryiterator.hasNext()) {
            Entry<String,String> entry =  entryiterator.next();
            String fileTypeHexValue = entry.getValue();
            if (filetypeHex.toUpperCase().startsWith(fileTypeHexValue)) {
                return entry.getKey();
            }
        }
        return null;
    }

    /**
     * Created on 2010-7-2  
     * <p>Discription:[isImage,判断文件是否为图片]</p> 
     * @param file
     * @return true 是 | false 否 
     * @author:[shixing_11@sina.com]
     */
    public static final boolean isImage(File file){
        boolean flag = false;
        try
        {
            BufferedImage bufreader = ImageIO.read(file);
            int width = bufreader.getWidth();
            int height = bufreader.getHeight();
            if(width==0 || height==0){
                flag = false;
            }else {
                flag = true;
            }
        }
        catch (IOException e)
        {
            flag = false;
        }catch (Exception e) {
            flag = false;
        }
        return flag;
    }
    /**
     * Created on 2010-7-1   
     * <p>Discription:[getFileHexString]</p>  
     * @param b
     * @return fileTypeHex
     * @author:[shixing_11@sina.com]
     */
    public final static String getFileHexString(byte[] b)
    {
        StringBuilder stringBuilder = new StringBuilder();
        if (b == null || b.length <= 0)
        {
            return null;
        }
        for (int i = 0; i < b.length; i++)
        {
            int v = b[i] & 0xFF;
            String hv = Integer.toHexString(v);
            if (hv.length() < 2)
            {
                stringBuilder.append(0);
            }
            stringBuilder.append(hv);
        }
        return stringBuilder.toString();
    }
}  